(A) The Zindler Company currently has a centralized billing system. Payments are made by all customers to the central billing location. It requires, on average, four days for customers mailed payments to reach the central location. An additional day and a half is required to process payments before a deposit can be made. The firm has a daily average collection of $500,000. The company has recently investigated the possibility of initiating a lockbox system. It has estimated that with such a system customers mailed payments would reach the receipt location two and one-half days sooner. Further, the processing time could be reduced by an additional day because each lockbox bank would pick up mailed deposits twice daily. a. Determine how much cash would be freed up (released) through the use of a lockbox system. b. Determine the annual gross dollar benefit of the lockbox system, assuming the firm could earn a 5 percent return on the released funds in Part (a) by investing in short term instruments. If the annual cost of the lockbox system will be $75,000, should such a system be initiated? (B) What are the major sources of external financing for business firms?